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Cages are ordered increasing from top to bottom and left to right.
The cages are digital, the last digit of the sum is in one of the cells.
Two cells have consecutive values, with the other non-consecutive so either C C NC or NC C C
R1C1, R23C1, R4C4, R8C7 and R8C8 are each in two cages.

1. Each cage must contain the last digit of the cage sum, with the other two digits totalling 10, so cage sums must be in the range 11 to 19.

11 = [128]
12 = [129/237]
13 = [238/346]
14 = [347]
No possible permutations for 15, since [456] would have three consecutive values
16 = [367]
17 = [278/467]
18 = [189/378]
19 = [289]

[I've gone straight into analysis of the cages; if I'd done Prelims based on step 1, some of the steps may have been slightly shorter.]

2a. The two cages at R1C1 share the same cell and are in the same nonet so must contain five different values. Only possibilities are [237/289] and [346/378] -> R1C1 = {23}
2b. The same applies for the two cages at R4C4 -> R4C4 = {23}
2c. Naked pair {23} in R1C1 + R4C4, locked for D\ and orange disjoint group
2d. R123C1 overlaps with R234C1, only possibilities using the permutations in step 2a for R123C1 are R123C1 = [237/346], R234C1 = [378/467] -> R1234C1 = [2378/3467], 3,7 locked for C1, 3 also locked for N1
2e. R123C1 = [237/346] -> diagonal cage at R1C1 = [289/378], 8 locked for N1 and D\
2f. Diagonal cage at R4C4 = [346] (only remaining possibility because no 3,8 in R5C5 + R6C6), placed for D\ -> R4C4 = 3, R5C5 = 4, placed for D/, R6C6 = 6, placed for pale green disjoint group
2g. Diagonal cage at R4C4 = [346] -> R456C4 = [378] -> R5C4 = 7, placed for yellow disjoint group, R6C4 = 8, placed for D/ and grey disjoint group
2h. R1C1 = 2 -> R1234C1 = [2378], R2C1 = 3, placed for yellow disjoint group, R3C1 = 7, placed for grey disjoint group and R4C1 = 8, placed for orange disjoint group
2i. R123C1 = [237] -> diagonal cage at R1C1 = [289] -> R2C2 = 8, placed for pink disjoint group and R3C3 = 9, placed for D\ and pale green disjoint group

3. Only possible permutations for cage at R4C5 are [128/129] -> R4C5 = 1, placed for green disjoint group, R5C6 = 2, placed for blue disjoint group, R5C7 = {89}

4. Only possible permutations for R789C7 are [128/129/189] -> R7C7 = 1, placed for orange disjoint group, R8C7 = {28}, R9C7 = 9, placed for grey disjoint group, R5C7 = 8, R8C7 = 2, placed for yellow disjoint group
[Or the more elegant way is R8C7 is first cell of R8C789, cannot be 8 -> R8C7 = 2.]

5. Only possible permutation for cage at R7C8 is [347] -> R7C8 = 3, placed for green disjoint group, R7C9 = 4, placed for purple disjoint group, R8C8 = 7, placed for pink disjoint group, R9C9 = 5, placed for pale green disjoint group

6. R8C7 = 2, R8C8 = 7 -> R8C789 = [278] -> R8C9 = 8, R9C8 = 6, placed for pale orange disjoint group, R9C1 = 1, placed for D/ and grey disjoint group

7. R9C3 = 8 (hidden single in C3), placed for pale green disjoint group -> cage at R7C3 = [238] (because no 7 in R8C2) -> R7C3 = 2, placed for D/ and purple disjoint group, R8C2 = 3, placed for D/

8. R1C9 = 7 (hidden single on D/), placed for purple disjoint group, R3C7 = 6 (hidden single on D/)
8a. Naked pair {45} in R12C7, locked for C7 and N3 -> R2C8 = 9, placed for D/ and pink disjoint group, R1C8 = 8, placed for green disjoint group, R46C7 = [73], R2C9 = 1, placed for blue disjoint group, R3C8 = 2, placed for pale orange disjoint group, R3C9 = 3, placed for pale green disjoint group, R4C6 = 5, placed for purple disjoint group, R4C3 = 6, R1C3 = 1, R4C8 = 4, placed for green disjoint group, R4C9 = 9, placed for purple disjoint group

9. Naked pair {15} in R5C28, locked for R5 -> R5C1 = 9, placed for yellow disjoint group
9a. Naked pair {45} in R2C37, locked for R2 -> R2C6 = 7

and the rest is naked singles, without using the diagonals and disjoint groups.